New sugarcane varieties to the rescue

For many sugarcane varieties, the rescuer can oftentimes be in need of rescue. Such is the case with LCP 85-384. The release of LCP 85-384 in 1993 was truly a hallmark of sugarcane breeding efforts in Louisiana. Its yield was 25 percent higher than the varieties grown at that time. It had exceptional stubbling (ratooning) ability, which allowed for the growing of more crops from each planting. And it was resistant to nearly all of Louisiana’s major diseases. All of these traits in one variety made the growing of sugarcane more profitable in a time when sugar prices were stagnant. LCP 85-384 became so popular that it was grown on 91 percent of Louisiana’s acreage in 2004.

With the average life span of a sugarcane variety at 10 years, all good things must come to an end. In recent years, brown rust began to appear in LCP 85-384, which had been resistant to the disease. Yields in the variety began a slow decline in many of the sugarcane- growing areas in Louisiana. New replacement varieties were needed. That job is left to the cooperative sugarcane breeding efforts of the LSU AgCenter, the U.S. Department of Agriculture’s Agricultural Research Service at Houma, La., and the American Sugar Cane League in Thibodaux, La.

Taking a look back Sugarcane production in Louisiana has a history of dominant varieties. In the early culture of sugarcane, only a few sugarcane varieties were available for cultivation by Louisiana sugarcane farmers. From 1751 until 1924, many predominant sugarcane varieties were grown. Black Cheribon, or Creole, was the dominant sugarcane variety for the first 100 years of sugarcane culture in Louisiana. This is the variety that Etienne DeBoré used when he first granulated sugar at his sugar plantation, which is now part of Audubon Park in New Orleans.

Otaheite, or Bourbon cane, was introduced 40 years later but was not as widely grown. Louisiana Purple and Louisiana Striped (Louisiana Ribbon Cane) were imported from Georgia in 1821 and were widely expanded because of their tolerance to frosts. D74 and D95 were imported from the Royal Agricultural Society of Demerara in 1894. All of these sugarcane varieties were introduced from other countries and sustained the Louisiana sugar industry for many years. Nearly all commercial varieties grown today can trace their parentage back to Black Cheribon.

From 1919 through 1926, sugarcane diseases such as mosaic, Pythium root rot and red rot diseases began to increase in the state. The effects were devastating as sugar production plummeted. In the mid 1920s – through efforts of the USDA Bureau of Plant Introductions, the Louisiana Agricultural Experiment Station, and local growers and mills – new foreign varieties were brought in to combat the negative effects of sugarcane diseases. Most notable were the POJ (Proefstation Oost Java) varieties.

In 1922, POJ 234 was obtained from quarantine houses in Washington, D.C., and POJ 213 was obtained in 1923. Both of these POJ varieties attained major status in Louisiana and saved the Louisiana sugar industry from the devastating results of mosaic and stalk rotting diseases.

The POJ varieties originated in Java and were hybrids between Saccharum officinarum primarily and Saccharum spontaneum. The hybridization among the two different species was an attempt to combat Sereh disease, which was severely affecting the sugarcane crop in Java. The POJ varieties were extremely successful and rejuvenated the Louisiana sugar industry.

Later, Co 281 (released in 1930) and Co 290 (released in 1933) were received from India, which again were the product of hybridizations among Saccharum officinarum and Saccharum spontaneum. Foreign variety introductions saved the Louisiana sugar industry, but everyone agreed that a long-term solution was needed – a local sugarcane breeding effort.

Sugarcane variety development through cross hybridization began in earnest in the mid 1920s. The cooperative efforts of the LSU AgCenter, USDAARS and the American Sugar Cane League were formalized in 1926 via the “Three Way Agreement,” which continues to this day. Crossing was done at Canal Point, Fla., where the warm waters of Lake Okeechobee provided an environment conducive for flowering in sugarcane. Seed was sent to Houma and Baton Rouge where the selection of new varieties for local Louisiana production began.

In the modern era with commercial variety development programs in place at Baton Rouge and Houma, several sugarcane varieties with improved yields and disease resistance have been made available for the past 80 years. These efforts have also led to dominant varieties over the years. CP 36-105 dominated the Louisiana sugarcane acreage in the late 1940s and early 1950s with a peak acreage of 56 percent in 1951; CP 44- 101 was dominant in the 1950s and early 1960s with a peak acreage of 53 percent in 1957; CP 52-68 was dominant in the 1960s with a peak acreage of 49 percent in 1968; CP 65-357 was dominant in the mid 1970s through the mid 1980s with a peak acreage of 71 percent in 1980; and CP 70-321 was dominant from the mid 1980s through the mid 1990s with a peak acreage of 49 percent in 1995. Finally, LCP 85-384 has been the leading sugarcane variety since 1998, achieving a peak acreage in 2004 of 91 percent.

Replacing LCP 85-384By 2003, it was apparent that LCP 85-384 was in need of replacement. The rescuer needed rescue. Replacing a sugarcane variety is no easy task because of the perennial nature of the crop, i.e. multiple crops can be harvested for many years from a single planting. The first variety to the rescue was HoCP 96- 540, a product of the cross between LCP 85-384 and LCP 86-454. HoCP 96-540 was released in 2003 and has been expanded rapidly to help replace acreage of LCP 85-384. In 2007, HoCP 96-540 was grown on 31 percent of the state’s acreage. And it continues to be a popular choice for growers during planting season. This new variety has high sugar per acre, responds well to ripeners and has a fairly erect growth habit.

In 2004, two new sugarcane varieties were released – L 97-128 and Ho 95-988. These new varieties continued to give growers a wider selection among varieties as more growers decreased their acreage of LCP 85-384. L 97-128 was released primarily for its early maturity and vigorous early season growth. Like HoCP 96-540, this variety has an erect growth habit. Ho 95-988 was released because of good sugar yields, stubbling ability and diversity in its genetic background. Upon release, Ho 95-988 was resistant to brown rust. Two years after release, however, high levels of brown rust began to appear in the variety. This underscores the need for successful breeding programs that can continually provide new varieties with increased yield potential and disease resistance.

In 2006, L 99-226 and L 99-233 were released to growers in Louisiana. In variety trials across the state, L 99-226 has typically had higher yields of sugar per acre than the other varieties tested. L 99-226 has a large stalk diameter, excellent yields of sugar per acre and high sugar per ton of cane. L 99-233 was released primarily because of its stubbling ability. Its yield in older stubble crops is excellent. L 99-233 has a high population of small diameter stalks. Both of these varieties tend to lodge (fall over in high winds) but have been harvested well by Louisiana’s combine harvesters.

HoCP 00-950 was released in 2007, primarily for its unsurpassed early and high sucrose content. Although the variety is relatively short early in the growing season, it has a good population of medium-sized stalks. HoCP 00-950’s yield of sugar per acre has been equal to that of HoCP 96-540.

The sugarcane breeder’s job is to provide a new and steady stream of varieties to the growers. No two varieties are alike. Growers need timely information regarding the management of new varieties. The more than 80 years of effort in sugarcane breeding have sustained a thriving industry in South Louisiana. Growers expect many things from sugarcane varieties including the ability to tolerate many stresses, such as drought, freezes and the occasional devastating hurricane. No single sugarcane variety is the answer to every problematic situation. To minimize risk, growers should plant several varieties. With a continuing cooperative effort in sugarcane breeding, the LSU AgCenter is poised to keep the Louisiana sugar industry sustainable for years to come.